18 December 2015

The Quick Clay Dam #nlpoli

A very short post by James Gordon at Uncle Gnarley contains a whole lot of information about the dam Muskrat Falls.

Gordon is a retired professional engineer with a 60 year career that took him to projects in 15 countries. He knows about hydro-electric dams. Six of Gordon’s projects won awards of excellence for design.

Gordon took a look at the plan for Muskrat Falls. Here are a couple of key points.

Nalcor plans to use the North Spur as a key part of the dam. “The hill consists of three layers of sand, and two layers of quick clay, sloping downstream, on a deep foundation of quick clay extending down to far below tidewater.”

Even after Nalcor takes measures to counteract the tendency of quick clay to liquify when it is disturbed, two layers of quick clay will remain within the main body of the dam.

“To my knowledge, Gordon wrote, “quick clay has never before been used to form part of a dam structure, nor has a dam been built on a quick clay foundation.”

“Since the design of the North Spur dam is without precedent, and the consequences of a failure are catastrophic, it becomes imperative to have the design reviewed by an independent panel of experts – a Review Board, to provide added assurance that the design is acceptable.”